Cellular Core walls

[larryplum]

Hi to all

I'm quoting a bathroom in a '60s house. All walls are of cellular core construction (50mm cardboard honeycomb core with plasterboard glued to both sides). When 50 year old tiles come off, the original plasterboard paper face will probably be ripped off the backing plaster and leave a mess of holes, exposed backing plaster and paper.

Will this definitely make it unsuitable for patching and directly re-tiling (300 x 400 7mm ceramic, full height)? I know you can't tile directly over backing plaster but i'm wondering what you would recommend from the following or any other ideas / similar experiences?

Seal with SBR or something similar and tile over all, including exposed backing plaster.
Skim all with multi-finish
Dot + dab new plasterboard over the top
Bond a thinner board such as 6mm Marmox over the top

Many thanks for your help

Larry

[deanotile]

Skim all with multi-finish (IMO) then SBR or something similar

[Dave]

If the option to over board is there, then that would be my route..

Plaster board will be fine and the cheapest route as well..

[whitebeam]

I would over board as well

[larryplum]

I'll see how it comes off and make decision. If it is pretty sound then I'll skim, otherwise I'll overboard.

If we're pushing to get the tiles on then I suppose it's quicker to over-board one day and tile the next rather than waiting for the skim to go off.

Thanks to all,

Larry